40 

NATURE 
[Marcu 11, 1915 

with strong experimental evidence. There are | 1861, when only twenty-two years of age, re- 
still to be found old-fashioned fishermen who have 
attained within a certain range to a wonderful sea- 
manship of an empirical sort; they have built up 
a body of associations from wind and from wave, 
from the sky and the “feel” of the sea, and they 
are seldom far out in finding their way home. And 
so it is with the higher ants, except that they 
work even more exclusively from an instinctive 
basis. 
It must be remembered that the orientation power 
of ants does not stand magically alone. Even brain- 
less animals adjust their body in a position of 
physiological equilibrium in relation to a stimulus 
of light or warmth or gravity-—a static orientation. 
When there is direction of locomotion in relation 
to an external stimulus, we speak of dynamic 
orientation. This dynamic orientation may be 
direct or indirect. It is direct when the stimulus 
or goal is within the range of immediate sense- 
perception, and it must be noted that for ants this 
range is only about a yard. Of this locomotor 
orientation there are various grades—tropistic, 
reflex, instinctive, and acquired, the first three ex- | 
pressing a hereditary predisposition, the fourth 
expressing the results of the individual's own learn- 
ing. On a higher level is indirect orientation, 
where the goal is beyond the range of direct 
sensory perception. A complex of imprints or 
memories, corresponding to the goal, functions in 
the animal’s sensorium, and forms the unifying 
centre of a whole series of imprints of the environ- 
ment of the goal. What leads the creature on 
from step to step—often quickly and, so to speak, 
unquestioningly, if no contradictory interruption 
occurs—is the recognition of localised stimuli 
corresponding to those of the unified reference 
series. The orientation implies a chain of recogni- 
tions, and the recognitions imply a registration of 
individual experiences. Without using Brun’s 
somewhat forbidding mnemic terminology, we 
cannot do justice to his carefully worked-out 
theory, but we have indicated its general nature. 
It is essentially what may be called psycho- 
biological, for he thinks of the organism as a 
historic being that trades with time, that en- 
registers imprints, and that has its past living in 
its present, as Bergson has accustomed us to say. 
These imprints, which the individual ant selectively 
accumulates, are not like sheets filed in a portfolio 
of reference ; they are interpenetrated with and kept 
alive by their meaning for the actual everyday life. 
»~—_—. 
PROF. JAMES GEIKIE, F.R:S. 
Y the death of Prof. James Geikie, Edinburgh 
and its university have been deprived of one 
of the most prominent of its men of science, and 
geology has lost a distinguished investigator and 
successful teacher. The son of J. S. Geikie, of 
Edinburgh, whose literary talent found expres- 
sion in a number of popular Scottish song's, the 
subject of this notice was educated at the high 
school and university of his native city, and in 
NOAeZO7,.VOlL. 95)| 

ceived an appointment upon the Geological 
Survey of Scotland, a service in which his elder 
brother, Archibald, had already been engaged for 
five years. James Geikie’s work as a surveyor 
lay chiefly in the south-west of Scotland, and in 
1869 he was promoted to be a district surveyor ; 
his studies seem to have been more particularly 
attracted, from a very early date, to the post- 
tertiary deposits, and in various papers in the 
scientific journals; as well as in the official 
memoirs of the survey, he published the results 
of his observations and his conclusions based upon 
them. Early in his career, James Geikie had 
become a great admirer and warm friend of 
Andrew Ramsay, then director of the English 
Geological Survey, and Ramsay’s _ theoretical 
| views and speculative suggestions found a stout 
supporter in the young Edinburgh geologist. In 
1876 the Colonial Office requested Ramsay to 
proceed to Gibraltar in order to report on the 
important question of its water-supply, and James 
Geikie was chosen to accompany and assist him. 
In addition to the valuable report made to the 
Government, the two geologists were able to con- 
tribute to scientific journals memoirs dealing with 
the geology of Gibraltar, and especially with the 
superficial and cavern-deposits, and their bearing 
on the history of the Mediterranean in post-ter- 
tiary times. 
In 1874 James Geikie had already published 
his conclusions concerning the history of the 
Glacial period in Britain in his well-known work, 
“The Great Ice Age,’ which has passed through 
three editions; and in 1881, after devoting his 
vacations to travel on both sides of the Atlantic, 
he extended the bearings of his views on the 
subject by the publication of his ‘“ Prehistoric 
Europe.” 
In the following year, however, James Geikie 
entered upon a new field of labour. The appoint- 
ment of his elder brother to the directorship of 
the Survey necessitated his vacation of the 
Murchison professorship of geology at Edin- 
burgh, and James Geikie received the appoint- 
ment, resigning his position on the Survey. Dur- 
ing his energetic and successful work of teaching, 
carried on for more than thirty years, he published 
a number of very valuable educational books : 
“Outlines of Geology,” of which four editions 
were called for; “Fragments of Earth Lore”; 
“Earth Sculpture,” two editions; and “ Structural 
and Field Geology,” three editions. His labours 
were not by any means limited to the special 
subject of his studies; he was one of the founders 
of the Royal Scottish Geographical Society, 
acting as editor of its journal, and for a time as 
president of the society. He was also for many 
years dean of the faculty of science in Edinburgh 
University. In 1875 he was elected a fellow of 
the Royal Society, and in 1889 received the Mur- 
chison medal of the Geological Society, while he 
was a member and correspondent of many scien- 
tific societies at home and abroad. 
It was not only in his numerous scientific writ- 
